[Tumoral sinuses or vascular channels in tumors. Legacy of B. Kellner]

The re-discovery of the tumor cell-lined vascular channels and the possible pathomechanism (vasculogenic mimicry) earned major attention in the literature. This phenomenon is known for 60 years following B.Kellner, later supported by several groups, however its significance is still not known. The two new form of tumor blood supply, the incorporation/apoptotic remodeling of the preexisting vasculature and the latest discovery of endothelial gene expression in tumor cells suggest two alternative mechanisms for the development of tumor sinuses or vascular channels. The existence of these sinuses in malignant tumors and their possible function in the nutrient supply may limit the application of the new anti-angiogenic therapies.